The SISCone jet algorithm is a seedless infrared-safe cone jet algorithm. There exists an implementation which is highly optimised for a large number of final state particles. However, in fixed-order perturbative calculations with a small number of final state particles, it turns out that the computer time needed for the jet clustering of this implementation is comparable to the computer time of the matrix elements. This article reports on an implementation of the SISCone algorithm optimised for low particle multiplicities. Program summary Program title: siscone_parton Catalogue identifier: AELF_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AELF_v1_0.html Program obtainable from: CPC Program Library, Queenʼs University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 2 No. of lines in distributed program, including test data, etc.: 1588 No. of bytes in distributed program, including test data, etc.: 41 164 Distribution format: tar.gz Programming language: C++ Computer: All Operating system: All RAM: Negligible for low parton multiplicities. Classification: 11.9 Nature of problem: Clustering of particles into jets. Solution method: Infrared-safe cone algorithm. Restrictions: Hard-coded restriction to 64 final state particles on 64-bit machines, but recommended to be used only for configurations with up to 10 final state particles. Running time: Depending on the number of final state particles, O ( μs ) for configurations up to 5 final state particles.