Standard Pistol grip Models: Option: A two-step rotation type (6mm type) with low speed and high speed is available. Letters A and B in the model number represent the type of bit. A: Applicable to double-end bits B or no indication: Applicable to double-end and single-end bits Rear exhaust Pistol grip Models: The rear exhaust direction is variable over 360 degrees, offering reduced noise and a cleaner working environment regardless of the direction of operation. Model No. DH-4.5PEA or DH-4.5PEB. Model No. D-5WPEA or D-5WPEB. Model No. D-6SPALE or D-6SPBLE. Model No. DH-6PLE. Model No. D-600SHEA or D-600SHEB. Model No. D-6WSHPE Model No. D-8WPE Standard Straight type Models: DH-4.5SA DH-4.5SB. D-6SSAEL D-6SSBEL DH-6SAELDH-6SBEL. D-6WSHS(A) or (B) type D-6WHCL(A) or (B) type. Standard Corner type Models: DH-4.5SA DH-4.5SB. D-6SSAEL D-6SSBEL DH-6SAEL DH-6SBEL. D-6WSHS (A) or (B) type D-6WHCL (A) or (B) type. Size of Driver bits Suitable all models with "A" in the model number. For exsample: D-6SPAL. Please instruct us to change it "A" type from "B" type Impact Driver models. All Yutanis standard models with "B" letter or without "A" letter in the model numbers are suitable to these bits. i.g. D-5WPE, D-6WSHPE, DH-6SEL. D-6SPBL, DH-6PL, DH-4.5S D-6SHPBL, D-6WHCL