BLUEROCK Tools Model 4Z1 2-Speed Concrete CORING Drill "AMAZON's Best Sellers Rank: #1 in Power Core Drills." Model 4Z1 is the highest selling, number 1 ranked concrete core drill on Amazon for a good reason! Specifications: Max Drilling Diameter: 4"Rated Voltage: 110VRated Frequency: 50-60HzRated Input Power: 1500WDual Speed: 2100rpm/950rpmArbor size is 1 1/4" 7UNC (Industry standard, most common coring bit mounting type)See our BLUEROCK brand core bits Contact BLUEROCK directly with any questionsFor concrete, asphalt and masonry drilling Structure and Features: Two-gear rotary speed is designed for drilling different size holes. The drill is fitted with a safety slip clutch #2 gear (2100rpm) is for smaller drill bits 1"-2"#1 gear (950rpm) is for larger drill bits 2"-4" This unit is designed to be an easy portable type drill for easy hand drillingNew improved water hose assembly with metal fittings and hardware for "wet" drillingCollar size is 2 23/64"Drill color is redBubble level on end of the drill for precision drillingRemovable shoulder rest attachmentAutomatic hold down switch for comfort Comes with a durable carrying case Arbor size is industry standard 1-1/4" 7UNC New improved water hose assembly with metal fittings and hardware for "wet" drilling NEW BLUEROCK Tools Model 4Z1 DUAL SPEED CORE DRILL DRILL BIT PICTURED IS NOT INCLUDED (See our separate listings for Bluerock brand core bits and our popular 1"-4" Wet Bit Set) 4Z1 Handheld Core Drill 4Z1 Handheld + 1"-4" Bit Set Package Deal 4Z1W/S Drill with Stand (No Bits) 4Z1W/S Drill with Stand + 1"-4" Bit Set Package Deal 8Z1 Core Drill with Stand (No Bits) Add to Cart Add to Cart Add to Cart Add to Cart Add to Cart Customer Reviews 4.5 out of 5 stars 258 4.4 out of 5 stars 76 4.1 out of 5 stars 46 4.7 out of 5 stars 11 4.0 out of 5 stars 70 Price $379.00$379.00 $639.00$639.00 $549.00$549.00 $829.00$829.00 $699.00$699.00 With Stand Handheld Only (See Optional Stand) Handheld Only (See Optional Stand) ✓ ✓ ✓ With Bits None 1", 2", 3", 4" Bit Set None 1", 2", 3", 4" Bit Set No Maximum Drilling Diameter Capacity 4" 4" 4" 4" 8"