Model 100 Piston Type Quick Change Tool Post Set This Model 100 Quick Change Tool Post Set: Essential set is supplied with: 1 x Model 100 Wedge Type Tool Post 2 x Model 100 Standard Tool Holder 1 x Model 100 Tool Holder with V- Groove Delux set is supplied complete with: 1 x Model 100 Wedge Type Tool Post 2 x Model 100 Standard Tool Holder 1 x Model 100 Tool Holder with V- Groove 1 x Model 100 Boring Tool Holder 1 x Model 100 Parting Tool Holder - Angled 1 x Model 100 Knurling Tool Holder The Model 100 quick change tool post system is designed specifically to work on bench lathes that have limited swing over the compound. This set is for lathes with up to 300mm/12" swing.The tool post and tool holders are of hardened steel construction for excellent rigidity and the mating faces are ground for better repeatability when changing tools. Specifications for the Tool Post: A: 2.1/2"B: 3.7/8"C: 2.1/4"D: ø14mm Dia., M14x1.5mm Thread Specifications for the Standard Tool Holder: This tool holder is designed to hold square tools up to 12mm.A: 38mmB: 14mmC: 11.5mmD: 25.4m Specifications for the V-Groove Tool Holder: This tool holder is designed to hold square tools up to 12mm and round tools diameter up to 11.5mm.A: 38mmB: 14mmC: 11.5mmD: 25.4mm Specifications for the Boring Tool Holder: This boring tool holder is designed to hold ø16mm round tools using the split sleeve (included) and ø19mm without the sleeve.A: 38mmB: 19mmC: ø16mm with sleeve, ø19mm without sleeve Specifications for the Parting Tool Holder (Angled): This parting tool holder will hold parting blade up to 3/16"x1/2".A: 1.1/2"B: 1/2"C: 3/16"mm Suitable Blades:HSS Parting-off Blade 3/32"x1/2"x4.1/2" Tapered M42 HSS-Co8 Parting-off Blade 2x13x110mm Specifications for the Knurling Tool Holder: A: 40mmB: 15mmC: 11mmD: 11.2mmE: 19mmF: 65mm